Railway signaling system



RAILWAY SIGNALING SYSTEM Filed sebi. 1965 -2 Sheets-Sheet', 1

26 ggf-ffii 78 aa mVvENroR WILLIAM M. Pfluno `Mmmm/s v85.19704 Y l w.M.PEL|No Y 3,546,448

32 v mm2` RAILWAY sIGNALING SYSTEM Filed"'se'p'".` 's ,l `196:5 l 2 sheets-sheet 2 j/zo . v v v v "n1, A` 'A' V .A H63 stamina. fy www *was 30E; N., m f y A PASS SENSITIVITY SWITCHING INDICATOR ADJUSTMENT CIRCUr FIGS ` mvENToR Y 54 1 WILLIAM M. PELlNo ATTRNEYS United States Patent O 3,546,448 RAILWAY SIGNALING SYSTEM William M. Pelino, Richmond, Va., assigner to Railtron Corporation, Richmond, Va. Filed Sept. 5, 1968, Ser. No. 757,738 Int. Cl. B61k 13/00 U.S. Cl. 246-246 13 Claims ABSTRACT F THE DISCLOSURE A railway signaling system including electromagnetic transducer means mounted adjacent a railroad track and adapted to provide no response to the vibrations attendant the passage of a normal vehicle but providing an electrical output in response to an impact by an improperly protruding vehicle member.

The invention pertains generally to railway signaling systems, and more particularly to railway signaling systems of the type utilized for monitoring the operating conditions of railway vehicles, such monitoring in accordance with this invention being adapted to the sensing of improperly protruding vehicle members upon passage of a train or the like past a sensing station at railside. A specific illustration of an application of this invention in the railway art is the detection of equipment improperly depending from a railroad car, and means for detecting such faults are commonly referred to as dragging equipment detectors.

The prior art has known many different types of socalled dragging equipment detectors, and one common form includes pivotally mounted paddles or similar members positioned on a railroad track at a location over which a passing trail will travel. The paddles extend upwardly from their pivotal mounts and are of such dimensions as to permit passage of a normal train vehicle thereover with no contact between the detector and the vehicle, while a vehicle with improperly depending or dragging equipment causes an indication or alarm by virtue of the engagement of the paddles as the vehicle passes thereover. This pivotal movement is translated by suitable mechanical means into, for example, a visual signal, indicating to railway personnel that the train is dragging equipment.

While such dragging equipment detectors of the prior art are satisfactory for some purposes, they are subject to malfunctions under certain operating conditions which render them all but useless. For example, in cold 4weather the pivotal paddles may freeze in position, resulting in a failure to exercise the required pivotal movement (and, sometimes, breakage of the paddles) upon being struck by a piece of dragging equipment. Also, a heavy blanket of snow settled around the prior art detectors sometimes inhibits such movement of the paddles. Further, the detectors of the prior art are an easy prey to vandalism.

The prior art has also provided other systems for monitoring a passing train for out-of-position equipment, whether such equipment is dragging equipment, is otherwise protruding or is in some other manner not properly positioned relative to the other parts of the train or relative to the rails over which the train passes. However, these other prior art systems are characterized by structural features similar to those described above, and are accordingly subject to the same or similar limitations.

It is therefore an object of this invention to provide a system for monitoring passing railway vehicles for out-ofposition equipment, without the limitations and malfunctions characteristic of the prior art systems.

More specifically, it is an object of this invention to provide an improved dragging equipment detector.

ICC

Further, it is an object of the present invention to provide an improved equipment for detecting loose flanged wheels on a railway vehicle.

A still further object of the invention is to provide an improved detector for railway vehicle wheels having worn or cupped treads.

In accordance with the present invention, these and other objects are achieved by means of a railway signaling system having electromagnetic transducer means mounted adjacent a railroad track in a position relative to the rails and vehicles passing thereover such that normal vehicles may pass without contact between the vehicle members and the transducer means or the mounting means therefor. However, upon the passage of railway vehicles having members thereof out-of-place and protruding beyond a position of normal clearance, such protruding members will strike the transducer assembly, and the impact results in an electrical output from the transducers.

The transducers in the signaling system of this invention are preferably mounted Within and protected by metallic strike plates or the like, and it is the strike plate which bears the impact of the protruding vehicle equipment. Upon such impact, the vibrations set up in the strike plate are transferred to the transducers as a mechanical input thereto, such input being characterized by a sharp sound having a steep wave front.

Since the vibrations attendant the passage of railway vehicles is characteristically a relatively low-frequency rumble, in sharp contrast to the higher audio frequency vibrations associated with the impact against the strike plates l(which are preferably of heavy steel construction), the present invention renders it possible to distinguish therebetween so as to provide an output indication as a result of an impact by improperly protruding vehicle equipment, while ignoring the low-frequency vibrations produced by the passage of normal vehicles.

In a preferred embodiment, the transducers and their associated strike plate assemblies are mounted on the railroad ties by means of vibration-absorbing members, such as neoprene bodies or the like, so as to isolate the strike plates and transducers from the ordinary low-frequency vibrations produced in the rails and ties by a passing train.

Further, the transducer means of a signaling system in accordance with this invention are connected to a suitable electric circuit, whereby the electrical outputs of the transducers, upon vibration of the strike plates associated therewith, are utilized to actuate an indicator or alarm. In the preferred embodiment, the electrical circuit includes an audiolter of high-pass characteristics, thus providing additional discrimination against the aforementioned low-frequency vibrations produced 'by the passage of heavy railroad vehicles,

In accordance with the preferred embodiment disclosed herein, the strike plate assemblies are mounted alongside the rails of a railroad track, both between and outside the rails. Thus, dragging vehicular equipment, whether between the rails or to the side thereof, will impinge upon the detector assemblies comprising the several strike plates and associated transducers.

Further, those portions of the strike plates between but adjacent the rails serve as loose-wheel detectors, since a flanged wheel which is loose on its axle may be displaced on its axle inwardly of the rail on which it is riding, resulting in an impact of the llange on such a Wheel with the adjacent strike plate.

In addition, the preferred embodiment of the present invention permits detection of excessive wheel tread wear, or cupped wheels, usually exhibited as high flanges on the internal rwheel flanges, or in the production of a second, external ange. In either case, the worn tread permits a portion of the wheel to extend further down the side of the rail, and the adjacent strike plate assembly is adapted to be struck thereby, affording an indication of the worn tread condition.

With the above considerations and objects in mind, the invention itself will now be described in connection with a preferred embodiment thereof, given by way of example and not of limitation, and with reference to the accompanying drawings, in which:

FIG. 1 is a plan view of a portion of a railroad track and bed, with a preferred embodiment of the railway signaling system of the present invention installed thereon,

FIG. 2 is a vertical section taken on line 2-2 in FIG. 1, and showing portions of a vehicle wheel truck assembly,

FIG. 3 is a vertical section taken on line 3-3 in FIG. 1,

FIG. 4 is a vertical section taken on line 4-4 in FIG. 1, and

FIG. 5 is a schematic block diagram of a preferred form of the electrical circuitry of the present invention.

Referring now particularly to FIG. l, the railside or roadbed installation of the detector equipment of the present invention is shown generally at 10, including rails 12 and 14 and the several ties 16. Mounted on and extending between two of the ties, 18 and 20, are a plurality of strike plates 22, 24 and 26, each of which is preferably formed of heavy steel plate or the like, and each of which has a pair of laterally extending flange members and a pair of faces therebetween which slope upwardly toward a central ridge, as may better be seen in FIGS. 3 and 4.

One or more transducers are mounted on the several strike plates, the transducers being mounted inside the central raised portion of each strike plate, so as to be protected thereby from mechanical impact, but so as to be vibrated thereby upon the establishment of vibrations in the strike plate. More specifically, two transducers 28 and 30 are shown mounted on the respective inner faces of the sloping central portions 32 and 34 of strike plate 26. Similarly, transducers 36, 38, 40, 42, 44 and 46 are mounted on the inner faces of the sloping central portions 48 and 50 of strike plate 24. Further, transducers 52 and 54 are similarly mounted on the respective inner faces of strike plate 22. In the case of each such transducer, it is securely mounted by any suitable means to the respective strike plate face, so that when a strike plate is vibrated in response to an impact with dragging equipment or the like, the transducer is similarly vibrated.

As may be seen in FIGS. 2, 3 and 4, in order to isolate the several strike plates 22, 24 and 26 from vibrations in the ties 18 and 20` such as would be produced by passage of a train over rails :12 and 14, respective pairs of resilient, vibration-damping pads 53, 55 and 56 are provided, positioned between the strike plate flange and the respective ties to which they are bolted or otherwise attached. As will be evident to those familiar with this art, the damping pads may be of any suitable material, though neoprene has proven particularly effective in use. Further, the pads could easily take the form of separate washers or the like positioned at each bolt, rather than the integral form shown in the drawings.

Referring now more specifically to FIG. 2, it can be seen that the central ridge 58 of strike plate 24 is foreshortened at each end, producing sloping end portions 60 and 62. The particular con-figuration of these beveled portions 60 and 62 is such as to be closely adjacent the flanges of the respective wheels of railway vehicles passing thereover on rails 12 and 14. As is shown in FIG. 2, the normal inner flange 64 of wheel 66 lies between rail 12 and beveled end 60 of strike plate 24, with adequate clearance between the flange and the strike plate. Similarly, normal inner flange 68 of wheel 70` lies between rail 14 and beveled end 62 of the strike plate, again, with sufficient clearance for the wheel to pass along the rail without contact with the strike plate. However, the flange of a wheel with a badly worn tread rides much lower alongside the rail, and upon passing the point of installation of strike plate 24, this high flange will strike the beveled end portion (60 or 62) of the plate. Also, when a wheel is loose on its axle, it is sometimes free to slide on its axle inwardly of the rails, in which case the Wheel flange will impinge upon the beveled ends of the strike plate.

A second sympton of badly worn wheel treads is the formation of a second flange, resulting from the cupping of the lateral section of the tread. That is to say, as the tread wears down, the wear occurs primarily in the center of the tread, between the inner flange and the outer side of the wheel. As this wear progresses, that portion of the tread adjacent the outside of the wheel, instead of being coplanar with the used tread portion, becomes a second flange relative to the worn tread, since the word portion is at a new, smaller radius than the relatively unused tread portion, which is still at the original tread radius. As the tread wear continues, this newly-formed or second flange extends further down the outside of the rail on which it rides.

In accordance with the present invention, the presence of second flanges or cupped wheels may be detected by means of the external strike plates 22 and 26. As shown in FIG. 2, the inner or railside ends of strike plates 22 and 26 are mounted adjacent the respective rails 12 and 14, and at a vertical position approximately level with the top of the rails. A resilient rod 72, preferably of steel or some other suitable material, is mounted by any convenient means 74 inside strike plate 22 at a position closely adjacent the central ridge thereof, with the remote end of rod 72 protruding slightly from the end of strike plate 22. This remote end of rod 72 lies adjacent the rail 12 at a position permitting unobstructed passage of the normal or non-worn wheel, but in which the rod will be struck and flexed by a second flange of a passing wheel with a worn tread. Flexure and release of the resilient rod 72 results in damped oscillations thereof, causing a momentary hammering of the rod against the strike plate 22, along with a corresponding mechanical input to the transducers 52 and 54 mounted thereon.

A similar resilient rod 76 (as shown in FIGS. 2` and 3) is mounted at 78 within strike plate 26, for detecting second flanges on wheels traversing rail 14.

FIG. 5 shows a preferred embodiment of the electrical circuit of the present invention. The plurality of transducers 28, 30, 36-46, 52 and 54 are shown connected in parallel to a single detection circuit comprising a highpass audio filter circuit 80, the output of which may conveniently be passed through a threshold or sensitivity adjusting circuit 82 before being applied to a suitable switching circuit 84. Any desired form of indicating means 86 may be connected to switching circuit 84. Preferably, switching circuit 84 comprises a silicon controlled rectifier switch, the many available forms of which are well-known to those skilled in the art. Obviously, a suitable power source is included in the circuit, though not shown in the drawings, for energizing the several portions thereof.

In the operation of the railway signaling system of this invention, with the installation completed at a suitable location along the railroad track, and with the indicating means installed at a desired location, either adjacent the railside installation or at some remote observation point, along with suitable interconnecting wiring, as indicated at 88, the passage of a normal train having no dragging equipment and no worn wheel treads or loose Wheels results in no electrical output from the several transducers, and no indication of fault in circuit 86, since none of the strike plates will have been struck by the passing vehicle. That is to say, in the absence of dragging equipment, there are no protruding vehicle members to impinge upon the several strike plates. Further, in the absence of worn wheel treads, the wheel flanges, whether the usual internal ange or a second tiange, will not depend suliiciently below the top of the rails to impinge upon either of the beveled end portions 60 and 62 of central strike plate 24 or upon the flexible rods 72 and 76 of the external strike plates 22 and 26, respectively. Further, in the absence of loose wheels which have become displaced inwardly on their axles, the central strike plate will not have been struck.

As described above, the vibration-damping mounting pads 53, 55 and 56 are such material and configuration as to isolate the several strike plates from the rumble or low audio frequency vibrations produced in the rails and ties by the passing of a train along the rails at the detector installation. Additionally, any such low frequency vibrations that may produce an output from one or more of the transducers will be nullilied by the high-pass lilter circuit 80, which passes to subsequent circuitry only the higher audio frequency signals corresponding to the sharp metallic impact indicating a fault of the type intended to be detected by the present invention.

Where, on the other hand, a train with dragging equipment passes over the detector installation of this invention, such protruding equipment will strike one or more of the strike plates 22, 24 and 26, resulting in a sharp vibration in the strike plate characterized by a steep wave front. As is well-known, such a wave form is rich in high frequency components, and it is these signal components which pass through lilter circuit 80 to enable switching circuit 84 to, in turn, produce an output indication or alarm in circuit 86.

Similarly, a loose and inwardly displaced wheel, or one with the high ilange characteristic of a wheel with a worn tread, upon passing the detector installation will impinge upon one of the beveled ends 60 and 62 of the central strike plate. Here, again, the vibrations set up in the strike plate, and, correspondingly, in the transducers 36-46 mounted thereon, are typically sharp sounds, with large high-frequency content. The resulting outputs of the transducers are fed, as before, through ilter circuit 80 to the threshold device 82, which is con veniently set to pass only signals of a significantly large amplitude, corresponding to an actual vehicle fault, as opposed to the smaller signal which would be produced, for example, by the strike plate having been kicked by some one walking along the track. Signals thus screened as to frequency and amplitude are applied to the switching circuit 84, which, when so actuated, sends an enabling signal to the indicator or alarm 86.

In addition, and in a similar manner, the passage of a wheel having a second or outer flange (as a result of tread wear) results in vibration of the corresponding rod 72 or 76 when it is struck, with the attendant vibrations set up in the associated strike plate being passed to the transducers mounted thereon. As before, the transducer output is passed through high-pass filter 80, threshold circuit 82 and switching circuit 84 to alarm 86.

The invention has been described above in some detail, and particularly in connection with a preferred embodiment thereof. However, it will be obvious to those skilled in the art that various modifications may be made as to such details. For example, the number of transducers, both total and per strike plate, may be varied to suit the convenience of a given installation. Further, the strike plate configuration may be different from that shown; for instance, the triangular cross-section of FIGS. 4

3 and 4 may be replaced by a plate which constitutes a gentle curve in cross-section, though the form shown is generally more economical to fabricate. Also, it may be desirable in some instances to provide more than one circuit per installation, so as to provide means for selectively indicating which transducer, or which group of transducers, has been actuated, thus providing an indication as to location of the vehicle fault.

In addition, while the preferred embodiment of the apparatus of the present invention has been shown in connection with a railside installation at a position lying under a passing train, it will be evident that strike plates of suitable configuration may also be mounted alongside the right-ofway in an erect position, so as to detect vehicular equipment improperly protruding laterally of the cars. Thus, the present invention may be employed to detect loose and nailing load chains, for example.

What is claimed is:

1. A railway signaling system for monitoring operating conditions of railway vehicles, comprising:

electromechanical transducer means for generating an electrical output upon the occurrence of a mechanical input thereto,

means mounting said transducer means contiguous a path traversed by such vehicles for inhibiting the transmission of low-frequency vibrations attendant the passage of normal vehicles, and

means electrically connected to said transducer means for providing an output indication upon the occurrence of an electrical output from said transducer means.

2. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 1, wherein said mounting means comprises a resilient vibration-damping member.

3. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 2, wherein said mounting means comprises a neoprene body.

4. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 1, wherein said transducer means comprise a plurality of electromagnetic transducers spaced laterally of such path.

5. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 1, wherein said transducer means is mounted adjacent a railway track in a position in which said transducer means will be struck by passing out-of-place vehicular equipment but missed by passing properly-positioned vehicular equipment.

6. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 5, wherein said transducer means is mounted @between the rails of such railroad track at a distance from an adjacent rail permitting non-contacting passage of the ange of a vehicle wheel occupying a normal position relative to suchrail but in the path of the flange of a vehicle wheel loose and displaced inwardly on its axle.

7. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 6, with a transducer means so mounted with respect to each rail of such railroad track.

8. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 6, wherein said transducer means comprises a strike plate so positioned with respect to such rail and an electromagnetic transducer mounted on said strike plate and adapted to be vibrated thereby.

9. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 5, wherein said transducer means is mounted adjacent the outer face of a rail of such railroad track at a position relative to such rail permitting non-contacting passage of normal vehicle wheels but in the path of the second llange characteristic of wheels having worn treads.

10. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 9, with a transducer means so mounted with respect to each rail of such track.

11. A railway signaling system for monitoring opering conditions of railway vehicles in accordance with claim 9, wherein said transducer means comprises a strike plate so positioned with respect to such rail and an electromagnetic transducer mounted on said strike plate and adapted to be vibrated thereby.

12. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 1, and including means connected between said transducer means and said indication means for blocking the passage of low-frequency audio signals from said transducer means to said indication means.

13. A railway signaling system for monitoring operating conditions of railway vehicles in accordance with claim 1, and including means connected between said transducer means and said indication means for blocking termined amplitude from said transducer means to said indication means.

References Cited ARTHUR L. LA POINT, Primary Examiner G. H. LIBMAN, Assistant Examiner U.S. C1. X.R.

the passage of electrical signals of less than a prede- 15 246-169;340-261 

